JP2005535871A - Solid state detector and optical system for microchip analyzer - Google Patents

Abstract

A miniaturized photoexcitation and detector system for detecting fluorescently labeled analytes in electrophoresis-based microchips and microarrays is provided. This system uses tiny integrated components, light collection, optical fluorescence filtering, and amorphous a-Si: H detectors for detection. Light collection is accomplished by proximity collection and / or a microlens system. Optical filtering is accomplished with an integrated optical filter. Detection is accomplished using an a-Si: H detector.

Description

Government support This invention was made with government support under grant number FG03-91ER61125 by the Ministry of Energy. The government has certain rights in this invention.

RELATED APPLICATION This application claims priority to US Provisional Application No. 60 / 385,770, filed June 3,2002.

BRIEF DESCRIPTION OF THE INVENTION The present invention relates generally to solid state detectors and optical systems for detecting fluorescently labeled analytes in microchip analyzers and microarrays, and in particular a-Si: H (hydrogenated amorphous silicon) light. The present invention relates to a detector, a filter, and a system using a microlens.

For small-scale bio-chemical analyzers that can perform high-throughput and high-performance assays (evaluation analysis) at sites that require analysis (point-of-care or point-of-analysis, hereinafter abbreviated as POC) There is a huge demand. Ultimately, these devices should be portable and disposable. For this purpose, capillary array electrophoresis (μCAE = microfabricated capillary array electronics) devices are promising candidates. As shown in Non-Patent Document 1 below, this μCAE has a greatly improved efficiency compared to conventional methods, such as amino acid analysis, protein and small sample analysis, DNA fragment separation, and DNA base sequencing. Can be used to perform a wide variety of analyses. Capillary electrophoresis (CE) measurements can be multiplexed to perform high-throughput genotyping on a large scale on a 96 to 384 lane μCAE instrument.
Micro Total Analysis Systems 2001 Ed. Ramsey & vanden Berg, Kluwer Academic Press Dordrecht, 2001

However, most μCAE devices still use conventional off-chip (not integrated on chip) laser-induced fluorescence detection systems, including photomultiplier tubes, CCDs, optical filters, lenses, lasers, and so on. Such a bulky detection system hinders the many benefits of POC analysis that are potentially possible with μCAE instruments. In order to realize a portable device, it is necessary to develop a small excitation and detection system. One means of achieving this is to use electrochemical detection as shown by Woolley et al. On-chip (integrated on the chip) electrochemical detection has attractive features such as simple structure and easy manufacturing, but electrochemical detection is more difficult than fluorescence detection. Detection sensitivity is not good. Furthermore, it is difficult to perform multiplexed assays such as specific protocols for DNA sequencing or single nucleotide polymorphism (SNP) detection.
Woolley et al. Analytical Chemistry, 70, 684-698 (1998)

Fluorescence detection is very sensitive, especially when combined with laser excitation. Multiplex detection is also feasible and is commonly used in modern DNA sequencers. Therefore, it is beneficial to devise a method for maintaining fluorescence detection for a bioanalytical chip and miniaturizing and integrating the excitation and detection system. Mastrangelo and his collaborators have reported a system in which a silicon photodiode containing a microfluidic system is fabricated directly on a silicon wafer, as shown in Non-Patent Documents 3 and 4 below. This monolithic fabrication complicates electrophoresis because of the conductivity of the Si substrate. In this case, the CE channel through which the fluid flowed had to be electrically isolated from the silicon substrate by depositing a material such as Parylene-C, SiN, or SiO2 on the channel. The cost of producing a system using single crystal silicon is relatively high due to the high cost of single crystal Si wafers and the need for multi-step processes. As shown in Non-Patent Document 5 below, Mariella reports a portable DNA analyzer that performs a real-time PCR (polymerase-chain-reaction) assay based on fluorescence detection using a homologous TAQ-man assay. However, his system is not designed for microfluidic channels and uses large samples of μL to mL.
MA Burns et al, Science, 282, 484 (1998) JR Webster et al., Analytical Chemistry, 73, 1622 (2001) Mariella, Jr., JALA, 6, 54 (2001)

In the present invention, a hydrogenated amorphous silicon (a-Si: H) photodiode is used in a compact integrated fluorescence detection system for a μCAE device. Such a-Si: H photodiodes can be deposited at very low temperatures (˜200 ° C.) by plasma decomposition of SiH ₄ gas or a mixture of SiH ₄ and H ₂ gas. The consistent low temperature process enables the direct deposition of a-Si: H photodiodes on inexpensive substrates such as glass or flexible plastic films as shown in Non-Patent Document 6 below. Furthermore, a-Si: H has many advantages in terms of mass production, patterning, and low production cost. Thin film transistors (TFTs) for active matrix liquid crystal displays and the following non-patent documents 7 and non- As shown in U.S. Pat. No. 6,057,086, this is demonstrated by the implementation of an image sensor array that combines a-Si: H photodiodes with TFT readout.
Ichikawa et al., J. Non-Cryst. Solids, 198-200, 1081 (1996) RA Street et al., MRS Symp. Proc: 192, 441 (1990) RA Street and LE Antonuk, IEEE Circuit and Devices, Vol. 9, No. 4, 38-42 (July 1993)

  It is an object of the present invention to provide an integrated detector and optical system for fluorescence detection in a microchip analyzer.

  Another object of the present invention is to provide an integrated detector system that utilizes a-Si: H photodetectors, optical filters, and microlenses for fluorescence detection in capillary electrophoresis devices.

  It is a further object of the present invention to provide an easily fabricated and inexpensive integrated detector and optical system for fluorescence detection in a microchip analyzer.

  The foregoing and other objects of the present invention are achieved by a detection system that utilizes an integrated a-Si: H photodiode and an optical filter to detect light emitted by a fluorescent group or functional group. In particular, the invention relates to the use of a system that integrates the use of a-Si: H detectors, optical filters, and lenses to detect fluorescently labeled compounds that are separated in an electrophoresis channel.

  The foregoing and other objects and features of the invention will be more clearly understood when read in conjunction with the following description, taken in conjunction with the accompanying drawings, in which:

  FIG. 1 schematically illustrates a capillary electrophoresis chip 11 having a separation channel 12 and a cross injection channel 13. A separation voltage of capillary electrophoresis is applied between the cathode 14 and the anode 16. The specimen or sample is introduced into the well 17 which is a well-like liquid reservoir, and when a voltage is applied between the wells 17 and 18, the specimen or sample moves on the injection channel. In accordance with well-known techniques, a sample is labeled with an appropriate fluorogenic group or functional group and emits a different frequency of fluorescence when the labeling component is illuminated with a frequency of light. The sample moves on the separation channel and is separated by electrophoresis, and emits fluorescence when the label component reaches the detection region irradiated with light. The emitted light is detected and identifies the label component as a function of the arrival time at the detector.

FIG. 2 shows an optical system that includes an integrated a-Si: H photodiode detector 21, an optical interference filter 22, and a lens 23. A photodiode detector is fabricated at low temperature by plasma decomposition of SiH ₄ gas or a mixture of SiH ₄ and H ₂ gas. This process makes it possible to produce a-Si: H photodiodes on an inexpensive substrate 24 such as glass or plastic. The production of the photodiode begins by first forming the metal electrode 26 by vapor deposition or sputtering of a metal layer such as chromium or aluminum. Next, an n-type a-Si: H layer 27, an intrinsic a-Si: H layer 28, and a p-type a-Si: H layer 29 are successively deposited. The second contact includes a deposited layer 31 of a transparent conductive oxide film such as ITO, SnO ₂ , Al or Ga doped ZnO. The order of the p-type layer and the n-type layer can be reversed. However, light injection from the p-layer side provides a high photocurrent due to the low mobility of holes compared to electrons. The optical interference filter 22 is formed by depositing a layer 32 of a material such as TiO / SiO ₂ / SiN of a selected thickness on quartz or other glass plate 33. The production of interference filters is well known in the art and will not be described further. In order to increase the collection efficiency, it is preferable to apply an anti-reflection coating 34 on the other side of the quartz plate. The microlens 36 completes the detection and optical system. The microlens 36 can be manufactured by injection molding the microlens 36 and coupling it to the plate 37. In this case, the plate 37 may be a part of the μCAE device. Alternatively, the lens 36 and support 37 can be made as a single piece by injection molding. The lens and support can be attached to the photodetector and filter to form an integrated assembly. The microlens 36 can be, for example, a convex lens, an aspherical lens, a hemispherical lens, a gradient refractive index lens, or a diffractive lens. These lenses serve to collimate the fluorescence emitted by the fluorescent groups or functional groups in the microchannel 12, as indicated by arrows 38. This enhances the collection of desired fluorescence and attenuation of the laser excitation light because the optical density of the interference filter depends on the incident angle of light. When the solid angle for collecting fluorescence is large, reflection at the boundary between the microplate and the lens can be removed by using a refractive index matching liquid.

  According to a preferred embodiment of the present invention, the photodiode 21 and the optical filter 22 have a pinhole 39. The excitation light beam 41 is projected onto the microchannel 12 through the glass substrate 24, the pinhole 39, and the lens 36. An anti-reflective coating (not shown) can be applied to the glass substrate, increasing the transmission efficiency of the light beam passing through the glass substrate and reducing scattered light. The light beam can be generated by a semiconductor laser (edge emitting or vertical cavity), a small conventional laser, or an LED. Since the metal contact or electrode 26 has a sufficient thickness, it acts as an aperture that defines the size of the transmitted beam. Thanks to the vertical laser excitation, laser light can be prevented from directly entering the optical filter and detector.

  The glass substrate 24 and the glass plate 37 can be supported at regular intervals by a filter assembly 32, 33, 34 attached to the spacer 21 (not shown) and the photodiode 21. This combination provides a detector and optical assembly that can be used to read the μCAE device 11 by placing the μCAE device 11 in each case in a cooperative relationship. Fluorescence emitted from the fluorescent group or functional group excited by the light beam 41 is collimated by the lens, and passes through the filter 22 that passes the fluorescence wavelength light and absorbs or reflects the excitation wavelength light. To the photodiode 21.

  FIG. 3 shows a μCAE device made by molding a lens directly on a μCAE device as indicated by the dashed line 42. Other reference numbers refer to the same parts as in FIG.

  In order to reduce the possibility of introducing scattered light from the side, it is important to minimize the distance between the optical filter and the a-Si: H detector. For this purpose, the filter layer is directed to the lower side of the quartz or transparent plate 33 and the a-Si: H detector is directed to the upper side of the glass substrate 24. To minimize the effects of laser scattered light, a metallic light shield can be formed inside the aperture or pinhole of the a-Si: H detector. Referring to FIG. 4, the photodiode 21 is formed on the lower electrode 26 having a small aperture 43. An insulating layer 44 such as SiN or oxide is formed on the outer peripheral surface of the photodiode 21 and the pinhole 39. Subsequently, a metal layer 46 such as aluminum connected to the upper electrode 31 is formed. This metal electrode also serves to block scattered light. FIG. 5 shows contact pads 47 and 48 for the upper and lower electrodes.

  The path of the laser beam can be reversed. There may also be advantages to irradiation of the CE channel from above. The transmitted beam passes through the detector hole. However, it will be more difficult to protect the a-Si: H detector from high intensity laser beams and scattering from the beams. Furthermore, strong forward scattered light may adversely affect the filter, especially during optical system alignment.

  FIG. 6 shows a device in which an optical filter and an a-Si: H detector are monolithically integrated based on the device structure shown in FIGS. Similar reference numbers are assigned to similar parts. The a-Si: H detector is durable against the coating temperature of some types of optical filters such as ZnS / YF3. The manufacturing process is as follows. First, after an a-Si: H photodiode is deposited on a glass substrate, a diffusion barrier layer 51 such as silicon oxide or silicon nitride is deposited. Next, an optical interference filter is coated thereon. Prior to filter coating, the diffusion barrier layer 51 is planarized by chemical mechanical polishing (CMP), which is important for the quality of the optical interference filter. It should also be noted that the metallic sidewall protection of the photodetector can be extended to the top of the optical interference filter, resulting in further reduction of laser light scattering.

  An array of detectors, filters, and lenses can be used to detect fluorescence from spaced apart electrophoresis channels 12. FIG. 7 shows an array of monolithically integrated optical filters and detectors coupled with μCAE channel 12. An array of vertical cavity surface emitting lasers (VCSEL) 52 is coupled with detectors and filters to emit excitation light. VCSEL arrays can be fabricated on the wafer 53 and are inherently scalable because individual laser diodes can be patterned by photolithography. The a-Si: H detector 21 and the filter 22 can also be monolithically integrated with the VCSEL array. Since the deposition temperature (<200 ° C.) of the a-Si: H detector and optical filter is very low, between a-Si: H and VCSEL (usually made of a compound semiconductor such as GaAs alloy or GaN alloy) This monolithic integration does not adversely affect the performance of VCSELs and a-Si: H detectors since the interdiffusion of elements in the is suppressed. In this embodiment, the lens 36 is formed as a part of the μCAE 11 by molding or the like, but may be a separate component or integrated with a detector array. Also note that alternatively a single laser can be directed to each sampling point by combining it with a radial or galvano scanner, several beam splitters, or an optical fiber array. Should. Obviously, since the array is two-dimensional, fluorescence can be detected along each of a number of channels. The fluorescence from a normal DNA array or protein array can be detected by the two-dimensional arrangement. The lens, filter, detector, and light source can be integrated into a single unit. Such an integrated device is used to continuously receive and read a μCAE apparatus having a large number of microchannels.

8 and 9 show two examples of monolithic integration of an optical filter and an a-Si: H detector on a μCAE device. In both structures, the a-Si: H detector must be fabricated on the filter, so the optical filter must withstand a-Si: H deposition temperature of ~ 200 ° C. A metal oxide multilayer interference filter such as SiO ₂ / TiO ₂ can satisfy this condition because the deposition temperature is as high as 250-300 ° C. Therefore, after the optical filter is fabricated by depositing the multilayer interference filter 32 on the μCAE device 11, the a-Si: H layer of the photodiode 21 is deposited on the barrier layer 51. If such an interference filter is used in a planar structure as shown in FIG. 8, the incident angle distribution of the laser scattered light to the filter will be important. If the detector suffers from laser light scattering from various angles, an edge absorbing filter or a combination of edge absorbing and interference filters can be used. To maintain a planar structure and good light collimation, a planar refractive index gradient lens (not shown) is used, on which an optical filter and an a-Si: H detector are monolithically integrated. You can also. It is also important to keep the detector close enough to the CE channel to increase the efficiency of light collection without a lens and keep the diode detector smaller.

Another way to reduce the wide angular distribution of scattered light is to make a filter on a sphere centered on the CE channel as shown in FIG. Light from the CE channel is incident perpendicular to the filter surface. This curved detector is removable as shown by the dashed line in FIG. In this case, the refractive index matching liquid is used between the lens 36 and the μCAE device 11. A combination of edge absorption filters and interference filters would be a reasonable choice. If the optical filter contains elements that are detrimental to a-Si: H detection, a barrier layer 51 such as silicon oxide or silicon nitride may be used to prevent the diffusion of harmful elements into the detector. Let's go. In order to insulate the detector from the high electric field, the diffusion barrier layer, ITO, may be replaced by _SnO 2, Al or Ga doped grounded transparent conductive oxide such as ZnO (TCO).

  a-Si: H PIN photodiodes have been shown to work very well even on curved surfaces, and the conformal properties of the film are also primarily high in plasma chemical vapor deposition (CVD) deposition pressure. Is good for. Similarly, using a higher operating pressure process such as CVD and sputtering could produce a uniform film thickness optical filter on the curved surface. To coat the curved surface with photoresist, a spray coating would be used rather than a conventional spin coating. Normal wafer exposure, such as contact and proximity, transfers the mask pattern to the photoresist. The pinhole on the upper curved surface can be close enough to the mask to allow pattern transfer. On the other hand, because the outer edges of the detector and optical filter are at a distance from the mask (several millimeters), the resolution of the mask pattern is degraded by diffraction effects. However, this is not a problem because the characteristic size of the device is large (several millimeters).

  10 and 11 show an alternative method of introducing laser light into the channel of the μCAE device. In FIG. 10, the channel 12 is irradiated by introducing a laser beam 56 in parallel with the plane of the μCAE device using the waveguide 57 directly through the μCAE substrate. A high refractive index thin film material is deposited on or in the glass substrate as a waveguide that intersects the CE channel 12. Thanks to the in-plane laser excitation, laser light is prevented from directly entering the filter 32 and the detector unit 21 without using pinholes. Laser excitation at an angle from the axis, particularly excitation at the Brewster angle, also has a similar effect as shown in FIG. The beam block 58 is used to prevent laser light from entering the filter 32 and the detector unit 21. Alternatively, the laser beam 56 can be introduced from the bottom by a mirror or prism towards the channel.

  If the detector is divided into two or more sectors and the optical filter is similarly segmented to accommodate different wavelengths, multicolor detection is possible. However, the light intensity per sectored detector is reduced. The a-Si: H detector can be replaced with a more sensitive detector such as a micro PMT, an avalanche photodiode (APD), or an APD array, regardless of whether it is a crystalline semiconductor or an amorphous semiconductor. Referring to FIGS. 12 and 13, a segmented filter / detector assembly is shown. This filter / detector includes three filters / detectors 61, 62, 63. Each of these filters / detectors is fabricated as described above, and like reference numerals are used for like parts.

  The detector can also be segmented in other arrangements. 14 and 15, the detectors 71, 72, and 73 are each divided into two sections 71a, 71b, 72a, 72b, 73a, and 73b. These two sections are arranged along capillary-channels 12a, 12b, 12c formed in a μCAE device 11 having a plurality of channels (only three are shown here). Each detector includes a light detector and a filter, and the filter transmits emitted light having a wavelength different from that of the adjacent detector. The detector is made as described above and therefore similar reference numbers are used. A lens 36 corresponds to each pair. Excitation light beam 76 is traversed along line 77. It will be apparent that other forms of multiple integrated multicolor detectors are within the teachings of the present invention.

  In the present invention, the use of a-Si: H photodiodes is emphasized for integrated detectors. However, it should be pointed out here that other glass compatible semiconductors such as hydrogenated microcrystalline Si (μc-Si: H) or low temperature grown poly-Si are also suitable as materials for integrated detectors. is there. μc-Si: H is formed by the same method under different conditions from a-Si: H. Poly-Si is produced by combining plasma CVD, LPCVD, or atmospheric pressure CVD with laser crystallization or metal-induced crystallization of amorphous silicon. Such Si materials exhibit much higher dark conductivity than a-Si: H, but are more sensitive in the red or infrared region and are more suitable for detecting red fluorescence. The sensitivity of a-Si: H in the red light region can be improved by incorporating Ge into a-Si: H and changing it to a-SiGe: H.

The a-Si: H integrated sensor optical system described here uses an electrophoretic device manufactured by all types of microfabrication techniques based on fluorescence detection, as referred to in Non-Patent Document 9 below. It is effective for DNA assays including conventional protein assays and arrays. Such electrophoresis devices include capillary electrophoresis, free zone electrophoresis, and isoelectric focusing. Possible applications include DNA fragment isolation, DNA sequencing, DNA pyrosequencing, polymorphism analysis, protein analysis, amino acid analysis, cell sorting, pathogen and infectious disease detection, food and water purity testing. In particular, fluorescence-based devices that perform large-scale multiplexed assays will benefit from integrated a-Si: H sensor systems combined with VCSEL technology due to ease of manufacture and reduced production costs. .
M. Schena ed., "Microarray Biochip Technology," Eaton Pub. Co., 1st Ed. (2000)

FIG. 1 schematically shows a capillary electrophoresis device produced by a microfabrication technique. FIG. 2 shows a photodetector, filter, and lens according to one embodiment of the present invention coupled to an electrophoretic device. FIG. 3 shows a photodetector, a filter, and a lens, which is part of the electrophoresis device. FIG. 4 is a detailed view of the photodetector used in the present invention. FIG. 5 is a top plan view of the photodetector of FIG. FIG. 6 shows a detection system in which a filter is integrated in the photodetector. FIG. 7 shows a system including a surface emitting laser (VCSEL) combined with an array of integrated filters and photodetectors of FIG. FIG. 8 shows the filter and photodetector integrated in the electrophoresis device. FIG. 9 shows the integrated device of FIG. 8 on a spherical surface. FIG. 10 shows a system in which excitation light is irradiated parallel to the plane of the electrophoresis device. FIG. 11 shows a system in which excitation light is introduced at an angle with respect to the plane of the electrophoresis device. FIG. 12 shows a filter / detector segmented to detect multiple wavelengths of light. FIG. 13 is a cross-sectional view taken along line 13-13 of FIG. FIG. 14 is a schematic diagram of another detector array. 15 is a cross-sectional view taken along line 15-15 in FIG.

Other

The original “fluorophore” has the meaning of “fluorescent group or functional group”.
The original “DNA sequence” has the meaning of “DNA sequencing”.
The original “well” means “well that is a well-like liquid reservoir”.

Claims (32)

  A detection system for detecting light emitted at a first wavelength by a fluorescent group or functional group responsive to excitation light of a second wavelength, wherein the detection system rejects the light of the second wavelength and the first wavelength A detector system comprising an integrated photodetector and an optical filter configured to pass light emitted by the optical detector to the photodetector.   The detector system of claim 1, wherein the photodetector is an a-Si: H photodiode.   3. A detector system according to claim 1 or 2, comprising a lens that collimates the emitted light and directs it to the optical filter.   The detector system of claim 3, wherein the lens is integrated with the monolithically integrated photodetector and filter.   The detector system according to claim 4, wherein the lens is selected from a convex lens, an aspherical lens, a hemispherical lens, a refractive index tilt lens, or a diffractive lens.   The filters and photodetectors are segmented so that each segmented filter passes light of a different wavelength than the other segmented filters, thereby emitting fluorescent groups or functional groups, respectively. The detector system according to claim 1, wherein the detector system detects light of different wavelengths.   The detector system of claim 6, comprising a lens that directs the emitted light to the segmented filter and photodetector.   The detector system according to claim 1, wherein the filter and the photodetector include an aperture, and the excitation light is guided to pass through the aperture.   9. The detector system of claim 8, comprising a VCSEL adjacent to the photodetector that generates light and causes it to pass through the aperture. A detector system for detecting an analyte labeled with an atomic group or functional group that fluoresces and emits light of a predetermined wavelength,
An integrated photodetector and an optical filter configured to direct light of the predetermined wavelength to the photodetector;
A laser for directing light beams of different wavelengths to the labeled analyte and emitting light of the predetermined wavelength;
A detector system comprising:   The detector system of claim 10, comprising a lens that collimates and directs the emitted light to the integrated photodetector and optical filter.   12. A detector system according to claim 10 or 11, wherein the photodetector includes an aperture for the light beam to pass through.   The detector system of claim 12, wherein the laser comprises a VCSEL.   The detector system of claim 12, wherein the VCSEL is integrated into the integrated photodetector and filter.   14. A detector system according to any one of claims 10 to 13, wherein the photodetector is an a-Si: H photodiode.   The detector system of claim 14, wherein the photodetector is an a-Si: H photodiode.   The detector system of claim 7, wherein the lens is integrated into the integrated photodetector and optical filter.   A detector system for detecting light emitted by an excited fluorogenic group or functional group that labels an analyte separated along a channel, wherein the emitted light is directed to the photodetector A detector system comprising a plurality of photodetectors and optical filters spaced along the channel.   19. The analyte of claim 18, wherein the analyte is labeled with fluorescent groups and functional groups that emit light of different wavelengths, and filters on different detectors are configured to direct different wavelengths of emitted light. Detector system.   The filters and photodetectors of each integrated photodetector and optical filter are segmented, and each segmented filter passes light of a different wavelength than the other segmented filters, thereby producing fluorescence The detector system according to claim 18, which detects light of different wavelengths emitted by the atomic groups or functional groups.   A detector system for detecting light emitted at a first wavelength in response to excitation light at a second wavelength, comprising a monolithically integrated photodetector and filter, wherein the filter emits at the first wavelength A detector system configured to pass the emitted light to a photodetector and reject the light of the second wavelength.   The detector system of claim 21, comprising a monolithically integrated lens that serves to direct the emitted light to the filter and photodetector. A detector system for detecting light emitted by fluorescent groups or functional groups at a plurality of spaced locations,
A detector system comprising an integrated system comprising a plurality of photodetectors and optical filters, each arranged to detect light emitted at a corresponding one of the spaced locations.   The detection according to claim 23, wherein each of the photodetector and the optical filter includes an aperture, and a laser projects light through the aperture to a corresponding fluorescent atomic group or functional group to emit light. System.   25. The detector of claim 24, wherein each of the photodetector and optical filter is segmented and receives light emitted by a fluorescent group or functional group disposed at a corresponding location in each segment. system.   26. The detector system of claim 25, wherein the filter corresponds to each section of the photodetector and passes light of different wavelengths.   27. The detector system of claim 26, wherein a lens corresponds to each of the segmented photodetectors and filters and directs light to the segmented filter.   26. The detector system according to any one of claims 23 to 25, wherein the plurality of photodetectors and filters are arranged in a one-dimensional array.   26. The detector system according to any one of claims 23 to 25, wherein the plurality of photodetectors and filters are arranged in a two-dimensional array. A detector system for detecting light of a first wavelength emitted by a fluorescent group or functional group in response to excitation by light of a second wavelength at a specific location in an adjacent electrophoresis channel,
A plurality of integrated photodetectors and optical filters arranged at specific locations in the adjacent channels and configured to reject light of the second wavelength and pass light emitted at the first wavelength A detector system comprising an integrated system.   The detector system of claim 1 including spaced apart locations along each of the channels and integrated photodetectors and optical filters at the identified locations along the channel.   32. A detector system according to claim 30 or 31, comprising means for applying excitation light at the specific location such that a fluorescent group or functional group at each specific location emits light.

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